Pyrexia and inflammation are indicatives of various disorders. Modern medicines are available for treatment of pyrexia, but they have few side effects. Several studies are ongoing Worldwide to search natural antipyretic agents with better efficacy and fewer or no side effects. This study was aimed at evaluating the antipyretic activity of Moringa oleifera bark in rabbits against E. coli induced pyrexia. Rectal temperature was recorded with digital thermometer at 0 h and E. coli suspension was injected. After 1 h again rectal temperature of the animals was recorded and hydro-alcoholic extract were administered to the treatment groups and paracetamol hydro-alcoholic 50 mg/kg orally to the positive control group. Then rectal temperature was recorded at the interval of one h for 4 h. After the drug administration (at h 1), the decrease in body temperature with the dose of 25mg/kg(-1) during next four h ranged between 1.9-2.6of as compared to the negative control. At the dose of 50mg/kg(-1) the decrease in temperature was 1.9-3.0 of. The decrease in body temperature at the dose of 100mg/kg(-1) was high, which ranged from 2.3-3.1of as compared to negative control. Paracetamol, a standard drug , also significantly lowered the temperature but Moringa oleifera at the concentration of 100mg/kg(-1) lowered the body temperature significantly as compared to the negative as well as positive control. Moringa oleifera bark has marked antipyretic activity in animal models and this strongly supports the ethnopharmacological uses of Moringa oleifera bark as an antipyretic plant.